Searched for: subject:"Perception"
(1 - 20 of 21)

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document
Wentink, M. (author), Correia GrĂ¡cio, B.J. (author), Bles, W. (author), TNO Defensie en Veiligheid (author)
In the real world in which we move around, inertial and visual motion are usually equal; what you see is what you feel. In a simulator, however, this is usually not the case. On the contrary, due to the relatively small motion space of even the largest simulators, the inertial motion cues must be filtered and scaled down considerably. Typically,...
conference paper 2009
document
Groen, E.L. (author), Bles, W. (author), TNO Technische Menskunde (author)
We examined to what extent body tilt may augment the perception of visually simulated linear self acceleration. Fourteen subjects judged visual motion profiles of fore-aft motion at four different frequencies between 0.04-0.33 Hz, and at three different acceleration amplitudes (0.44, 0.88 and 1.76 m/s2). Simultaneously, subjects were tilted...
article 2004
document
Bos, J.E. (author), Bles, W. (author), TNO Technische Menskunde (author)
Motion sickness is not only elicited by certain kinds of self-motion, but also by motion of a visual scene. In case of the latter, optokinetic drums are often used and a visual-vestibular conflict is assumed to cause the sickness. When the rotation axis is Earth vertical however, different studies show different results. Here, we propose that...
article 2004
document
Groen, E.L. (author), de Graaf, B. (author), Bles, W. (author), Bos, J.E. (author), Kooi, F. (author), TNO Technische Menskunde (author)
In this paper we give an outline of the ground course on spatial disorientation that TNO Human Factor provides for military student aviators of the Royal Netherlands Airforce. During this one-day course a variety of laboratory equipment is used to let students experience and understand different disorienting phenomena and to make them aware of...
conference paper 2003
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Bos, J.E. (author), Bles, W. (author), Hosman, R.J.A.W. (author), Groen, E.L. (author), TNO Technische Menskunde (author)
We here present a model including visual-vestibular interactions describing the basic properties of the human spatial orientation system. It hence also explains and describes spatial disorientation. The model indicates that spatial orientation should at least be characterised by four variables: linear acceleration and velocity, angular velocity,...
conference paper 2003
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Bos, J.E. (author), Bles, W. (author), Dallinga, R.P. (author), TNO Technische Menskunde (author)
Human performance at sea generally decreases with increasing severity of seasickness. Seasickness predictions are therefore a valuable tool for both design and operational purposes. Elaborating a previous contribution to this conference, we now present motion sickness predictions induced by combined sway and roll motions. The model used is based...
conference paper 2002
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Bles, W. (author), Boer, L.C. (author), TNO Technische Menskunde (author)
conference paper 2001
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Bles, W. (author), Nooy, S.A.E. (author), Boer, L.C. (author), TNO Technische Menskunde (author)
bookPart 2001
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Bos, J.E. (author), Bles, W. (author), Hosman, R.J.A.W. (author)
conference paper 2001
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TNO Technische Menskunde (author), Wertheim, A.H. (author), Mesland, B.S. (author), Bles, W. (author)
On the basis of models of otolith functioning, one would expect that, during sinusoidal linear self-motion in darkness, percepts of body tilt are experienced. However, this is normally not the case, which suggests that the otoliths are not responsive to small deviations from the vertical of the gravito-inertial force vector acting on them. Here...
article 2001
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Groen, E.L. (author), Bos, J.E. (author), de Graaf, J.E. (author), Bles, W. (author)
According to the widely accepted sensory conflict theory, motion sickness arises in situations in which "the motion signals transmitted by the eyes, the vestibular system, and the non-vestibular proprioceptors are at variance either with one another or with what is expected from previous experience." Consequently, several types of sensory...
conference paper 1999
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Bles, W. (author), Bos, J.E. (author), de Graaf, J.E. (author), Groen, E.L. (author), Wertheim, A.H. (author), TNO Technische Menskunde (author)
In reviewing the various forms of motion sickness the classical sensory rearrangement theory has been redefined by demonstrating that only one type of conflict is necessary and sufficient to explain all different kinds of motion sickness. A mathematical description is provided from the summarizing statement that "All situations which provoke...
article 1998
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Bos, J.E. (author), Bles, W. (author), TNO Technische Menskunde (author)
In an attempt to predict the amount of motion sickness given any kind of motion stimulus, we describe a model using explicit knowledge of the vestibular system. First, the generally accepted conflict theory is restated in terms of a conflict between a vertical as perceived by the sense organs like the vestibular system, and the subjective...
article 1998
document
Wertheim, A.H. (author), Bos, J.E. (author), Bles, W. (author), TNO Technische Menskunde (author)
The purpose of the present study was to test the traditional assumption that sea sickness is uniquely provoked by heave motion characteristics, pitch and roll movements being ineffective. In an experi-ment with a ship motion simulator subjects were exposed to pitch, and roll motions in combination with rather weak heave motions that have no...
article 1998
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de Graaf, B. (author), Bles, W. (author), Bos, J.E. (author), TNO Technische Menskunde (author)
In an experiment with seventeen subjects interactions of visual roll motion stimuli and vestibular body tilt stimuli were examined in determining the subjective vertical. Interindi-vidual differences in weighting the visual information were observed, but in general visual and vestibular responses added in setting the vertical. Despite the...
article 1998
document
Bles, W. (author), TNO Technische Menskunde (author)
Coriolis effects are notorious in relation to disorientation and motion sickness in aircrew. A review is provided of experimental data on these Coriolis effects, including the modulatory effects of adding visual or somatosensory rotatory motion information. A vector analysis of the consequences of head movements during somatosensory, visual and...
article 1998
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Bles, W. (author), de Graaf, B. (author), Bos, J.E. (author), TNO Technische Menskunde (author)
article 1996
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Bos, J.E. (author), de Graaf, B. (author), Bles, W. (author), Wertheim, A.H. (author), TNO Technische Menskunde (author)
article 1996
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Groen, E. (author), de Graaf, B. (author), Bles, W. (author), Bos, J.E. (author), TNO Technische Menskunde (author)
To assess a possible otolith contribution to effects observed following prolonged expo-sure to hyper gravity, we used video-oculography to measure ocular torsion during static and dynamic conditions of lateral body tilt (roll) before and after one hour of centrifugation with a Gx-load of 3G. Static tilt (from 0 to 57 deg. to either side) showed...
article 1996
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de Graaf, B. (author), Bles, W. (author), Bos, J.E. (author), Groen, E. (author), TNO Technische Menskunde (author)
A hypothesis about the position of the eyes under weightlessness could be verified during parabolic flight. The eyes, namely, tort a few degrees inwards (cyclo-versional behaviour) during zero-G. The data suggest that the saccular otoliths contribute to ocular torsion.
conference paper 1995
Searched for: subject:"Perception"
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